Text Categorization or Classification

Though the automated classification (categorization) of texts has been flourishing in the last decade or so, has a history, which dates back to about 1960. The incredible increase in online documents, which has been mostly due to the expanding internet, has renewed the interest in automated document classification and data mining. While text classification in the beginning was based mainly on heuristic methods, i.e. applying a set of rules based on expert knowledge, nowadays the focus has turned to fully automatic learning and even clustering methods.

Definition of Text Classification:

Let C = { c₁, c₂, ... c_m} be a set of categories (classes) and D = { d₁, d₂, ... d_n} a set of documents.